This invention relates to cement-based compositions and, more particularly, to cement-based compositions used in construction and building applications.
Cement-based materials are used in a variety of building and construction applications, such a concrete, mortar, grout and concrete patching. These materials typically are a mixture a finely-ground hydraulic cement, such as Portland cement, and an aggregate and/or diluent, such as sand, and set to a hardened state after admixing with water or another hardening agent. For some applications, such materials are modified by adding latex-type materials to improve the adhesive, strength, flexibility and curing properties.
Cement-based building materials are formulated with different ingredients and/or concentration of ingredients to provide properties in the hardened product desired for a particular application(s). Thus, one material may be suitable for use as a ceramic tile grout, but completely unsuitable as a masonry mortar. During manufacture, different type building materials may be blended in the same equipment and packaged in the same type bag or carton. Many cement-based building materials have the same or substantially the same appearance to the naked eye which can lead to one type product being inadvertently introduced into the package for another type. Relatively extensive testing may be required to verify that particular type material is in the proper package. Thus, the capability of making a simple, inexpensive verification is highly desirable.
Once a cement-based building material has hardened after application, it is, at the very best, extremely difficult to positively and reliably determine the specific type of building material used or the supplier of that material. Consequently, when a manufacturer is alleged to have distributed a faulty product which caused a failed installation, it is virtually impossible for the manufacturer to verify that the correct type material was used in accordance with its specifications or recommendation or that the material in question is even one it produces.
Tracer materials have been used in a variety of processes and products to determine the presence and/or concentration of specific materials in the product. This is exemplified by U.S. Pat. Nos. 4,707,453, 4,656,049 and 4,654,165. None of these patents suggests using a tracer material in cement-based materials for the purpose and in the manner described below.